题解

#include <bits/stdc++.h>
using namespace std;
long long q(int a,int b){
    int c=max(a,b);
    if(c%min(a,b)==0) return min(a,b);
    else{
        c%=min(a,b);
        return q(c,min(a,b));
    }
}
int main(){
    long long a,b;
    cin>>a>>b;
    cout<<q(a,b);
    return 0;
}